Determinants of Acidobacteria activity inferred from the relative abundances of 16S rRNA transcripts in German grassland and forest soils

16S rRNA genes and transcripts of Acidobacteria were investigated in 57 grassland and forest soils of three different geographic regions. Acidobacteria contributed 9-31% of bacterial 16S rRNA genes whereas the relative abundances of the respective transcripts were 4-16%. The specific cellular 16S rRNA content (determined as molar ratio of rRNA:rRNA genes) ranged between 3 and 80, indicating a low in situ growth rate. Correlations with flagellate numbers, vascular plant diversity and soil respiration suggest that biotic interactions are important determinants of Acidobacteria 16S rRNA transcript abundances in soils. While the phylogenetic composition of Acidobacteria differed significantly between grassland and forest soils, high throughput denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphism fingerprinting detected 16S rRNA transcripts of most phylotypes in situ. Partial least squares regression suggested that chemical soil conditions such as pH, total nitrogen, C:N ratio, ammonia concentrations and total phosphorus affect the composition of this active fraction of Acidobacteria. Transcript abundance for individual Acidobacteria phylotypes was found to correlate with particular physicochemical (pH, temperature, nitrogen or phosphorus) and, most notably, biological parameters (respiration rates, abundances of ciliates or amoebae, vascular plant diversity), providing culture-independent evidence for a distinct niche specialization of different Acidobacteria even from the same subdivision.

Chrétiens ›Roman de Perceval ou le Conte du Graal‹ und Wolframs ›Parzival‹. Ihre Überlieferung und textkritische Erschließung

This article discusses the manuscript transmission of Chrétien’s Roman de Perceval ou le Conte du Graal and Wolfram’s Parzival in terms of their textual tradition and editorial criticism. It shows that the most recent edition of the Old French Perceval (K. Busby 1993) can be viewed as a landmark of the art of conventional editing that appeared at the peak of the discussion of ‘New Philology’ and took its own position in this context. At the same time, the Perceval was subject of critical studies based on the principle of ‘unrooted trees’ that questioned the genealogical concept of traditional ‘Lachmannian’ stemmatology. Conversely, a new edition of Wolfram’s Parzival, based on all known manuscripts, remained a desideratum for decades in German studies. Specific research on the textual tradition played a rather marginal role for a long time, but has been reinforced in the recent years in the context of a new critical edition presenting the totality of manuscripts as well as different textual versions in electronic form. The concept of ‘unrooted trees’ visualizing relationships of manuscript readings can be integrated in this concept. The article gives an overview of these methods, presents examples of editorial techniques, and develops ideas on how to combine the research on the manuscript tradition of both the German text and its French counterpart.

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In Germanistic philological editing, theoretical discussion on the commentary assumes traditionally a secondary role compared to the manifold contributions on other subjects of textual philology. Already in 1924, Georg Witkowski admonished to enhance scholarly debates on the commentary, and the claim has since been repeated several times. This paper reflects current discussions in the context of contemporary annotation practice, wishing to trigger new considerations of how the intellectual genesis of text and the contexts of literary works can be adequately illustrated in the commentaries.

Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D-1), Simpson's dominance (D-2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P.lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.

Factors influencing fixed retention practices in German-speaking Switzerland : A survey.

AIM Several surveys evaluate different retention approaches among orthodontists, but none exist for general dentists. The primary aim of this survey was to record the preferred fixed retainer designs and retention protocols amongst general dentists and orthodontists in Switzerland. A secondary aim was to investigate whether retention patterns were associated with parameters such as gender, university of graduation, time in practice, and specialist status. METHODS An anonymized questionnaire was distributed to general dentists (n = 401) and orthodontists (n = 398) practicing in the German-speaking part of Switzerland. A total of 768 questionnaires could be delivered, 562 (73.2 %) were returned and evaluated. Descriptive statistics were performed and responses to questions of interest were converted to binary outcomes and analyzed using multiple logistic regression. Any associations between the answers and gender, university of graduation (Swiss or foreign), years in practice, and specialist status (orthodontist/general dentist) were assessed. RESULTS Almost all responding orthodontists (98.0 %) and nearly a third of general dentists (29.6 %) reported bonding fixed retainers regularly. The answers were not associated with the practitioner's gender. The university of graduation and number of years in practice had a moderate impact on the responses. The answers were mostly influenced by specialist status. CONCLUSION Graduation school, years in practice, and specialist status influence retention protocol, and evidence-based guidelines for fixed retention should be issued to minimize these effects. Based on the observation that bonding and maintenance of retainers are also performed by general dentists, these guidelines should be taught in dental school and not during post-graduate training.

The Transmission of Manuscripts and the Genetics of Texts. A new critical edition of Wolfram von Eschenbach’s Parzival

The discussion on the New Philology triggered by French and North American scholars in the last decade of the 20th century emphasized the material character of textual transmission inside and outside the written evidences of medieval manuscripts by downgrading the active role of the historical author. However, the reception of the ideas propagated by the New Philology adherents was rather divided. Some researchers questioned its innovative status (K. Stackmann: “Neue Philologie?”), others saw a new era of the “powers of philology” evoked (H.-U. Gumbrecht). Besides the debates on the New Philology another concept of textual materiality strengthened in the last decade, maintaining that textual alterations somewhat relate to biogenetic mutations. In a matter of fact, phenomena such as genetic and textual variation, gene recombination and ‘contamination’ (the mixing of different exemplars in one manuscript text) share common features. The paper discusses to what extent the biogenetic concepts can be used for evaluating manifestations of textual production (as the approach of ‘critique génétique’ does) and of textual transmission (as the phylogenetic analysis of manuscript variation does). In this context yet the genealogical concept of stemmatology – the treelike representation of textual development abhorred by the New Philology adepts – might prove to be useful for describing the history of texts. The textual material to be analyzed will be drawn from the Parzival Project, which is currently preparing a new electronic edition of Wolfram von Eschenbach’s Parzival novel written shortly after 1200 and transmitted in numerous manuscripts up to the age of printing (www.parzival.unibe.ch). Researches of the project have actually resulted in suggesting that the advanced knowledge of the manuscript transmission yields a more precise idea on the author’s own writing process.

Assessing Difficulties in Career Decision Making Among Swiss Adolescents with the German My Vocational Situation Scale

Assessing problems in career decision making among adolescents is important for career guidance and research. The present study is the first to investigate among Swiss adolescents the factor structure and convergent validity in relation to personality of the German-language adaptation of the My Vocational Situation Scale. Two preliminary studies (N = 217) suggested that using a 5-point Likert scale response format would increase scale reliability. The confirmatory factor analyses in the main study with two cohorts (n = 341, eighth grade; n = 303, eleventh grade) confirmed that four main factors, which assess problems with identity, decision making, information, and perceived barriers, underlie the data. The barriers factor was differentiated into aspired vocation and personal situation. Construct validity was supported by significant relationships between favorable personality characteristics (emotional stability, extraversion, agreeableness, conscientiousness, generalized self-efficacy, and internal locus of control) and fewer problems. The results suggest that the vocational identity and barriers scales can be fruitfully applied to research on and the practice of career counseling with adolescents.